The present invention relates to a fixture for clamping rectangular workpieces and/or tools.
Clamping fixtures for rectangular tools and/or workpieces are known which consist of two oppositely directed, approximately semi-cylindrical rotatable chuck jaws, which are moveable toward and away from each other by exterior supporting blocks and collets. Each of the chuck jaws is mounted so as to rotate in an arc of about 180.degree. about a longitudinal axis, set at right angles to the direction of compression of the supporting blocks. Each of the chuck jaws is provided with a seat in which the workpiece is received. The seat is defined by two clamping surfaces set at right angles to one another which intersect in a common edge running longitudinally parallel to but offset from the axis of rotation of the chuck jaw.
Such a clamping fixture is generally found in British Pat. No. 960,684. The clamping jaws of this fixture are secured by retaining springs in the collets, so that the latter can only perform a slight rotary movement. This fixture is therefore only suitable for clamping square workpieces. However, if the range of rotation of the clamping jaws within the supporting collets is increased, it is possible to set up some rectangular pieces, provided they have sides of approximately the same dimensions. Notwithstanding, since the axis of rotation of each of the clamping jaws lies outside the intersecting edge of the two surfaces forming the clamping seat, the setting up of even such limited rectangular workpieces results in placing the diagonal of the workpiece offset from the direction of compressive movement or adjustment produced by the shifting of the supporting blocks. Thus, the direction of the clamping force on the workpiece does not coincide with the diagonal and this in turn leads to non-symmetrical force reactions. Consequently, the precise positioning of the workpiece being set up, is in all cases severely impaired.
It is the object of the present invention, to provide an improved clamping fixture overcoming the disadvantages of the prior art and one in which rectangular workpieces and/or tools can be precisely clamped.
It is another object of the present invention, to provide improved clamping fixture, by which rectangular workpieces or tools, having different facial dimensions and side ratios of different values, can be mounted, so that notwithstanding these differences, their diagonals would be always aligned parallel to the clamping direction.
It is still another object of the present invention, to provide a clamping fixture which provides for a symmetrical transfer of the clamping forces to rectangular workpieces or tools and by which each subsequent workpiece or tool can be set up in exactly the same manner.
The foregoing objects, together with other objects and advantages of the present invention, will be obvious from the following disclosure.